Elihu thomson



, (No Model.) v

. E. THOMSON.

DYNAMO ELECTRIC MACHINE.

QW OO A8 1|- 7., 1Q) 1v... ui?. JF d DU .Tu n DU .fu a P UNITED STATES YPATENT OFFICE..

THOMSON-HOUSTON ELECTRIC COMPANY.

DYNAlVlO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent No. 281,416, dated July1'7, 1888. Application filed January 22, 1883. (No model.)

.T all whom it may concern:

k-Be it known that I, ELIHU THoMsoN, a citizen of the United States, anda resident of New Britain, in the county of Hartford and State ofConnecticut, have invented certain new and useful Improvements inDynamo-Electric Generators, of which the following is a specification.

My invention relates, first, to the construction of an armature woundwith two or more coils for dynamo-electric and magneto-electricgenerators in which the tension of the generated current is great; andit consists in improvements designed to make the use of such currentspracticable and easy and to increase the durabilityof the apparatus.

My improvement consists, first, in the use of a cylinder-ring orspherical armature-core or equivalent shell of iron made without anyconducting metallic projections, or at least without any suchprojections that approach near to the outer layers of insulated wiresurrounding` said core,I and in winding said core, constructed as above,with insulated wire in such a manner that high electric potentials insaid wire shall be found only on the outside layers of said winding andfarthest from said core. The object attained by the construction is theprevention of short-circuit faults through the armature-core, frompoints of high potential of insulated wire to others of opposite orlower potential on a different part of said core. The armature-coreitself is in certain cases,l in addition insulated from all other partsof the machine. By combining the latter feature with my mode of winding,I secure the safest possible construction. This latter combination isespecially valuable where a number of machines are run in series, andwhere a possibility of leak in the foundations upon which they restexists.

Another part of my invention consists in using for those layers of thearmature-coil that lie'- nearest the core of the armature a coarser wirethan is used for the outside layers, both wires being connected inseries and acting together, thereby equalizing the resistance.- By thisarrangement the temperature of the underlying layers (which latter arenot eX- posed to the free air, and therefore are liable to become moreheated than the outer layers) is kept down. Two or more gradations ofwire may be used, the finer being always nearer the outer surface. Thisconstruction tends to a uniform distribution of heat, and renders theparts less liable to displacement and damage from unequal expansionproduced by the higher temperature of the internal layers, which isliable to occur when Vthe interior and exterior coils are of the samesize as is ordinarily the case.

Another part of my invention consists in the application to the outerwires of an armature of an interwoven string or tape, which binds saidouter layers together and practically solidiiies the winding andprevents disturbance of its position by accident or otherwise.

Figure 1 is a vertical section parallel to the shaft X of a cylindricalarmature containing one feature of my invention. Fig. 2 is an end viewofthe same. Fig. 3 illustrates my mode of winding, to be hereinafterdescribed. Fig. 4 illustrates my mode of winding for equalization oftemperature. Fig. 5 illustrates a modification ofthe method shown inFig. 4. Fig. 6 is a cross-section of a portion of an armature throughthe wires of the saine when Wound after the plan illustrated in Fig. 4.Figs. 7 and 8 show the method of binding the outer layers ofarmature-wire. Fig. 9 shows another application of the same binding tothe larmature-wires. Fig. 10 illustrates the application of the variousparts of my invention to an annular or ring armature.

vIn Fig. lis shown in section an ordinary cylindrical core or carrier,II, of iron, supported concentrically with the shaft X, but vinsulatedfrom it. The end plates or flanges, F F, support the core I, which is ofany usual construction. Outside said core the armature coils ofinsulated copper are wound. One of said coils is. indicated at C C, andseveral coils are in my invention supposed to be so wound, but indifferent angular positions as ordinarily. All the coils amgwopgd as tobring their inner layers or wires nearest the core I of lowest electricpotential, and this is effected by a union of all of said inner wireterminals or wires from the inner layers of the armature into a commonjoint, J. It will be seen that when this is done the difference of pov28h/isti tential between the lower and inner layers of one coil and thatof any other will be slight, and that there will be little, if any,tendency to perforate the insulation and follow the iron core I I to anyother point. This is not so in armatures used with several coils, inwhich an accumulation of potential takes place as the current passessuccessively through one coil after another, entering one coil near theiron core, leaving such coil from its outer layers, thence passing tothe inner layers of the next coil, and leaving as before, and so onthrough several coils, so that wire at great differences of potential isnear the core at different points. The same disadvantage exists whereiron proj ections extend outward and approximate closely to the outerlayers at high potential, and is a source of great danger to insulationin high-tension machines.

I do not use in my invention cores having iron projection approximatingclosely to the outer layersof my winding. I may, however, employ ironprojections when the distance of such projections from the outer layersis made great, or when there is a free air-space separating suchprojections and layers.

Fig. 2 shows an end view of an armature like that of Fig. l wound withthree coils, the free terminals of which are also the terminals from theouter layers of armature-wire,- which armature has the greatestdifferences of electric potential at the points before described. Theseterminals a b c are carried to the cominutator, or, when reversedcurrents are obtained, to insulated rings, as usual.

Fig. 3 is a symbolic ligure showing thatthe three coils AB C have theirinner terminals joined at J, while the outer terminals are free forconveying current from the coils. This disposition brings the highesttension at the greatest distance apart and far from any otherconductors, insuring durability and freedom from leakages.

Fig. 4L shows the preferred disposition of the masses of coppercomposing the wire of a coil, A. The wire leaving J is larger in sizethan that at a., or the inner layers are of heavier wire than the outerones. This prevents undue generation of heat iu the inner layers, whilethe outer layers, having greater exposure for cooling, are, though ofiiner wire, kept cool by the circulation of air around them.

Fig. 5 shows an equivalent construction, in which the outer layers areofsingle wirey of convenient size, while the inner layers are of doublewire, the combined section of which is greater than the outer wire.

Fig. 6 shows the saine subjeet-matter'as Fig. 4, but the wires lying inlayers outside the iron core are shown cut transversely and as of threesizes, the outer being the finest wire.

Figs. 7 and 9 illustrate myimproved method of giving stability to theouter layers of wire constituting parts of the armature, and preventingthem from becoming displaced. Two or more tapes or cords, t t, areinterwoven with the wires, alternately passing above and below the wireconvolutions, as shown in Fig. 9,where the wires are separated forelearness. This is seen also in Fig. S at tt, where the tapebinds thecoils at the end of the armature to prevent its displacement duringrevolution around the axis X.

Fig. l() shows a ring-armature wound as before-namely, the ends orterminals leaving a joint, J, are those from the inncrlayers ofthearmature-coils C C2 C C, while the outer lay ers have their terminalsfree to be carried to a commutator of any suitable construction.projections extend from the core ofthe armature, and these projectionsare of iron, the winding is accomplished, so that as successive layersare wound on the armature-coil the distance between the projections p pand said outer layers is increased, as shown at s s.

Vhat I claim as my invention isl. In an armature of cylindrical,aiuuilar, or spherical form, made without conducting projections, orwithout projections that approach near to the outer layersot'armaturewire, a system of two or more coils wound, as described, soas to bring the highest electric potential upon the outer layers of saidwindings only, as and for the purpose set forth.

2. In an armature of cylindrical, annular, or spherical forni, madewithout conducting projections, or without projections that approachnear to the outer layers of armaturewire, a system of two or more coilsthe terminals from the inner layers of which are `joined, while theterminals from the outer layers are carried to the commutator, asdescribed.

3. In a dynamo-electric or magneto-electric machine, an armature-coilthe inner layers of which are of coarser wire or conductor than theouter layers, for the purpose set forth.

4. The combination, with the outer layers of wire in the armature, ofone or more tapes or cords interwoven with said layers, substantially asset forth.

5. As a means for preventing displacement of the coils of wire upon anarmature, an interwoven tape or tapes uniting and solidifying contiguousconvolutions of wire, substantially as set forth.

Signed at New Britain, in the county oi' 'Witnesses E. WVILBUR Rien, IV.O. VAKEFIELD.

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